Three of Robin van Persie's former Arsenal team-mates will be especially irritated by his move to Man United - because the Dutchman won't be able to finish his recent Cologne lesson on a new ball trick that none of them have yet mastered.

New Arsenal striker Lukas Podolski was forced to conduct his farewell lap for Cologne with a riot police escort as his final game for the club was overshadowed by ugly scenes in the RheinEnergieStadion.